Magnetically induced stiffening for soft robotics

Area of Science:

• Robotics
• Materials Science
• Mechanical Engineering

Background:

• Soft robots require variable stiffness for human-centric applications.
• Existing methods like pneumatic jamming and thermal phase change have limitations in portability and response time.
• Magnetorheological fluids offer potential for controllable stiffness.

Purpose of the Study:

• To develop a magnetically-controlled variable stiffening mechanism for soft robots.
• To combine the benefits of jamming-based stiffening with magnetorheological fluids.
• To enable electronically controlled stiffness for safer human-robot interaction.

Main Methods:

• A hybrid approach using magnetorheological fluid and jamming principles.
• Investigating the effect of magnetic field strength on stiffening via fluid yield stress and magnet clamping.
• Developing an analytical model to predict stiffness based on magnetic field strength.
• Demonstrating electronic stiffness control using electropermanent magnets.

Main Results:

• The proposed method successfully achieved variable stiffness in magnetorheological jamming beams.
• Magnetic field strength was shown to significantly influence the stiffening effect.
• An analytical model accurately predicted the stiffness response.
• Electronic control of stiffness was demonstrated.

Conclusions:

• Magnetically-controlled stiffening offers a promising solution for variable stiffness in soft robots.
• This approach overcomes limitations of existing methods, enhancing portability and response time.
• The developed mechanism is a step towards safer, electronically-driven soft robots for wearable applications.